INTRODUCTION The diagnosis and therapy of blunt cerebrovascular injuries has become a focus since improved imaging technology allows adequate description of the injury. Although it represents a rare injury the long-term complications can be fatal but mostly prevented by adequate treatment. CASE PRESENTATION A 33-year-old Caucasian man fell down a 7-meter scarp after losing control of his quad...

The aim of this study is to compare the effect of various restorative materials on fracture resistance in maxillary premolars. Premolars (n = 64) with no restorations or cracks were selected. MOD cavities were prepared considering the buccolingual width to be equal to half of the intercuspal distance. The specimens were randomly divided into 8 groups, 8 specimens each: group A intact teeth, gro...

The effect of width of the restoration, tooth position, and amalgam type on the fracture of the margins of 13- to 14-year-old, high-copper, amalgam restorations was evaluated. The evaluation assessed 193 photographs of restorations by use of ridit analysis and a rank-ordering test. The results indicated that the width of the restoration was the predominant factor and that tooth position and the...

In this study, electrical, thermal and mechanical properties of multi-walled carbon nanotubes (CNTs) reinforced Epon 862 epoxy have been evaluated. Firstly, 0.1, 0.2, 0.3, and 0.4 wt% CNT were infused into epoxy through a high intensity ultrasonic liquid processor and then mixed with EpiCure curing agent W using a high speed mechanical agitator. Electric conductivity, dynamic mechanical analysi...

Natural fracture growth plays an important role in shale-oil enrichment. Systematically investigating features and their controlling factors reservoirs is essential for accurately predicting distribution. The of distribution the continental shale Qingshankou Formation Songliao Basin, China, were systematically analyzed based on quantitative characterization outcrops cores. Strata-confined fract...

Crack surfaces are usually rough on various scales, and sensitive to loading stresses hence significantly affecting the mechanical properties of cracked rocks. We design a number dry- fluid-saturated numerical samples investigate roughness influence crack elastic stiffness. The fracture surface is characterized by non-uniform radii. calculate moduli finite-element simulation. Comparisons with t...

The aim of this study was to investigate interexaminer and intraexaminer agreement in the replacement decision for Class I amalgam restorations. Three examiners evaluated the restorations clinically and with bitewing radiographs. One hundred and twelve restorations were evaluated for secondary caries, body fracture, deficient anatomic form (contour), ditched margins, and marginal overhangs. Aft...

An equation was developed from studies of single-pass wear and fracture toughness of filled and unfilled dental restorative resins and dental amalgams relating the sliding frictional force F to the normal load N, fracture toughness, modulus of elasticity, yield strength and slider diameter. This equation was of the same form as that reported for viscoelastic materials (F = KW). Friction was cau...

T he widespread use of pins to provide retention for amalgam restorations began with Markley’s’ description of cemented stainless steel pins. In 1966 the selfthreading pin technique was introduced.2 Unlike cemented pins, which rely on cement to hold them in place, self-threading pins are larger than the pinhole and are threaded into it. The cutting action of the threads retains self-threading p...